The 'Fighter' singer has recently unveiled a new, much slimmer figure after losing 30lbs and credits her new body to practicing the spiritual healing technique.

A source told the National Enquirer: ''It's a Japanese method for healing the body, emotions, mind and spirit. Christina also credits a low-carb diet and yoga workouts for her new look, but Reiki puts her mind in a good place and gives her the discipline to eat healthy and maintain weight loss. She sees a Reiki mater for private sessions three times a week.''

'The Voice' USA judge, 32, has previously said she feels ''refreshed'' by her weight loss because she's been able to spend more time with her five-year-old son Max.

She said: ''I got to have, finally, a break and spend some time with my son ... being able to breathe and have time away outside of the camera and get to the nitty-gritty of all things real and personal [allowed me to come] back refreshed.''